This invention relates generally to electrical connectors, and more particularly to such a device for connecting a conductor, preferably in the form of a stranded wire, to a binding post forming part of the invention, the binding post being typically mounted on a supporting wall or other surface, here illustratively described as one of the enclosing walls of a loudspeaker.
Conventional electrical connectors including binding posts of various types have been proposed and used in the past, frequently requiring the use of hand tools such as pliers or a screwdriver in order to form the connection, and normally requiring that the user employ both hands in making the connection. In accordance with the present invention there is provided a connector having an internal binding post, specially configured as described below, together with an insulating cap mounted upon the binding post and rotatable through a limited angle relative thereto. The cap is provided with a bore extending therethrough, disposed eccentrically relative to the axis of the binding post and cap, into which an electrical lead can be inserted, with a bared portion of conductor at the end of the lead. The present connector finds particular application in making connection with a stranded conductor, as is used in carrying electricity as in a sound system, and will be described herein in connection with its use in connecting a wire to a loudspeaker. However, the invention is also applicable for connecting a solid conductor.
In accordance with a preferred form of the invention hereinafter described and shown in detail, a binding post is fixed to a supporting surface, and has a shank portion, which may be threaded, terminating in a terminal suitable for having an internal wire permanently soldered or affixed thereto. The upper or outer portion of the binding post includes a cam mounted upon a flange, the flange being desirably slightly elliptical about the central axis of the binding post. The insulator cap mentioned above, having an eccentric bore for receiving the conductor to be connected in accordance with the invention, also has a central bore which serves as a socket for rotatably receiving therein the uppermost stud portion of the binding post, in order to properly position the cap relative to the binding post. The lower portion of the cap includes a body having an internal downwardly open cavity formed therein defined by a generally cylindrical skirt, and the lower edge of the skirt includes fastening means, desirable in the form of inwardly extending protrusions, which snap over the flange of the binding post in order to maintain the cap attached to, but rotatable relative to the binding post. The material of the cap is of a suitable plastic dielectric material having some degree of elastic deformability, and the inside diameter of the lower portion of the skirt is such that it deforms slightly in receiving therein the flange, the relationship between the inner face of the skirt and the flange being compressional, so that the present connector resists inadvertent unfastening as a result, for example, of vibration or the like. At the same time, the connector can be easily disconnected by the user, by twisting the cap relative to the binding post.
The cap is easily rotatable by the user through a suitable angle, preferably between 90.degree. and 180.degree., and stop means are provided on the cap for inner engagement with elements of the binding post, in order to limit angular movement of the cap relative to the binding post.
The object of the present invention is accordingly to disclose and provide a novel electrical connector. Other objects and purposes of the invention are to provide an electrical connector having a cap of dielectric material provided with a conductor-receiving bore therethrough, the cap being mounted upon a fixed binding post for limited angular rotation relative to the binding post; to provide in such a device a binding post having a cam formed thereon, and configurations on the inner surface of the dielectric cap for forcing the bared end of a conductor into electrical contact with the outer cammed surface of the binding post, during rotation of the cap relative to the binding post; to provide in such a device means for ensuring frictional resistance to inadvertent rotation of the cap relative to the binding post; to provide such a device easily useable by the user with only one hand, and in an environment where the user may not be able to see the connector and conductor; to provide such a device of unusual economy of manufacture and reliability in use; and for other and additional purposes as will be understood from a study of the following description of a preferred embodiment of the invention, taken in connection with the accompanying drawings.